<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>for in遍历对象的属性</title>
</head>
<body>
    <script>
        let books=[
            {bookname:'《JavaScrips前端开发案例教程》'},
            {bookname:'《Node.js核心基础教程》'},
            {bookname:'《HTML5移动Web开发》'}
        ]
        for(let a in books)
        {
            document.write(books[a].bookname+'<br>')
        }

    </script>
</body>
</html>